import net.egork.io.IOUtils;
import net.egork.utils.Solver;
import net.egork.utils.io.InputReader;

import java.io.PrintWriter;

public class Task90C implements Solver {
	public void solve(int testNumber, InputReader in, PrintWriter out) {

        int n = in.readInt();
        int m = in.readInt();
        int k = in.readInt();
        int a[] = IOUtils.readIntArray(in, n);

        if (n % 2 == 0) {
            out.println(0);
            return;
        }

        int max = Integer.MAX_VALUE;
        for (int i = 0; i < n; i += 2)
            max = Math.min(max, a[i]);
        int required = (n + 1) / 2;
        long ans = Math.min(max, ((long) m / required) * k);
        out.println(ans);
	}
}


